Plasterer's requirement rejected in Isleworth (6)
I believe the answer is:
trowel
'plasterer's requirement' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'rejected in isleworth' is the wordplay.
'rejected' is a reversal indicator.
'in' indicates a hidden word.
'lewort' is hidden within 'isleworth'.
'lewort' back-to-front is 'TROWEL'.
Can you help me to learn more?
(Other definitions for trowel that I've seen before include "small digger" , "Fabled place of great wealth" , "Platsterer's tool" , "Garden implement" , "Brickie holds it" .)